Slashdot Log In
Banked Blood May Not Be As Effective As Hoped
Posted by
kdawson
on Tue Oct 09, 2007 04:20 PM
from the round-up-the-usual-vampires dept.
from the round-up-the-usual-vampires dept.
URSpider alerts us to two separate research reports published in the Proceedings of the National Academy of Sciences pointing to the rapid breakdown of nitric oxide in donated blood as a reason why such blood loses its ability to transfer oxygen, and is sometime implicated in problems such as strokes and heart attacks. Nitric oxide depletion is significant after 3 hours of storage; yet current guidelines allow for storing donated blood for up to 42 days. The article notes: "Several of the researchers, including Stamler, have consulting and/or equity relationships with Nitrox/N30, a company developing nitric oxide based therapies."
Related Stories
This discussion has been archived.
No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
Full
Abbreviated
Hidden
Loading... please wait.
pros and cons (Score:5, Insightful)
Die due to running out of blood.
Survive because someone donated blood.
I realise that the length of time is a factor and you want the freshest possible, but beggars can't be choosers.
Re:pros and cons (Score:4, Insightful)
Parent
Re: (Score:2)
Re:pros and cons (Score:5, Informative)
The problem listed in the article is an increase in heart attacks and strokes post-transfusion. Time's more complete article [time.com] says that 25% of blood donor recipients have heart attacks within the 30 days post-transfusion, as opposed to 8% of patients who came in to the emergency with similar conditions, but did not get a blood transfusion.
When the problem shows itself over the 30 days post-transfusion, it can be hard for medical researchers to notice and research the issue. I'd suggest (assuming this research has been done properly), having my probability of MI increase from less than 1 in 10 to 1 in 4, would make me want them to consider altering the requirements, whether it be by providing more new blood, or by artificially adding Nitric Oxide (not Nitrous Oxide, as the summary claims).
Parent
Re: (Score:2, Insightful)
I would guess that people who received blood transfusions are also at higher risk for pneumonia and cancer.
And if NO w
Re: (Score:3, Interesting)
It'll be interesting to see whether the research proves that oral nitrates will be effect
NO dilates blood vessel and not always desired. (Score:5, Informative)
In natural circumstance, for exemple, it is produced during effort to divert blood to region where it is needed (because the adrenaline has a global effect of closing the blood vessels).
In medicine, products that create NO like Nitroglycerin are used to dilate vessels and increase blood flow to the heart in case of angor (not enough blood in the heart muscle because of cholestrerol-clogged arteries).
Sildenafil (Viagra) is an inhibitor which stops the destruction of NO, thus maintaining enough level of NO, so the vessels are dilate and there's enough blood flow to fill the penis and provide erection.
Yes, if there's not enough NO, a stroke may appear. That's why Nitro-glycerine is given to avoid it.
Yes, transfused blood is more dense than other substance that can be injected to compsensate blood loss (other substance = Ringer solution = physiological serum = basically isotonic sterile salty water with some additional sugar thrown in). And this increased viscosity may increase the risk of stroke.
Now, just concentrate for a moment : to whom are you going to transfuse blood / perfuse physiological serum ?
People who lost a lot of liquid (bleeding wounds, burns, etc.).
Why ?
Because their blood pressure is dropping and there is a risk of shock (= schematically, not enough blood pressure to irrigate brain and other important organs).
Now, all
Now to go back to the situation, all the people from the study cited by the Times had (supposedly - didn't read the actual study yet) low blood pressure. Some got blood transfusion, other did not (I suppose they recieved physiological solutions instead).
25% of the blood reciever had heart attacks.
It may be caused, as the sponsor would like us to believe (the company makes NO products), because NO binds to hemoglobine [wikipedia.org] and helps releasing oxygen. And thus the transfused blood was useless because it didn't have enough NO to release enough oxygen. In this case we should buy the company's NO products.
BUT
- Why didn't the physiological receiving patient had problems ? Physiological serum doesn't carry oxygen at all. If NO-less blood is useless at transporting oxygen, non-oxygen-transporting solutions should too...
- Where they compared against a 3rd group receiving only fresh (NO-rich) blood ? No. Where they compared against 4th group receiving NO enriched non-fresh blood ? No, this was only done in lab rats.
- NO is something produced by the body when needed and has a short life (3 hours as they said in stored sample). Presence or absence of NO in the blood can hardly explain stroke happening 30 days later, after 3 hours the NO contained in the transfused blood is already degraded and replaced by NO produced by the patient.
- Other ligands can also increase release of O2 : temperature, CO2, products of degradation of glucose. Hemoglobine has a lot of different way to guess that some body regions are burning a lot of oxygen and that the hemoglobin-bound oxygen should be released more easily.
- Also note that their explanation can only account for the brain hypoxia (lack of oxygen), not the stroke itself (clogged vessels).
On the othe
Parent
Re: (Score:3, Informative)
Re: (Score:3, Funny)
Re: (Score:3, Interesting)
ays that 25% of blood donor recipients have heart attacks within the 30 days post-transfusion, as opposed to 8% of patients who came in to the emergency with similar conditions, but did not get a blood transfusion.
First, those figures apply only to heart disease patients, so are likely on the edge anyway. The stats presented do need to be looked at, but there can be many reasons for the differences that have nothing to do with NO levels. For example, increasing the blood viscosity (by adding red blood c
Re:pros and cons (Score:5, Insightful)
Let me weigh up the situation here:
Die due to running out of blood.
Survive because someone donated blood.
Or the third possibility, which this article is likely addressing:
Receive a nitric oxide injection that's packaged along with the blood in addition to the blood transfusion, and have an even better chance of surviving than blood alone.
Why do you think there's only two possibilities?
Parent
Re: (Score:2)
Re: (Score:3, Insightful)
I don't see injections of nitric oxide being pushed as, the nitric oxide pathway is the same one that Viagra works on.
Re:libs and cons (Score:2)
Clearly the first possibility is the conservative policy, because we shouldn't be playing god with people's blood. The second possibility is the liberal policy, because we get medical treatment, but it's substandard and poorly thought out. There may be a third possibility, but hippies throwing away their vote on it is pointless and will just help fascist hospital administrators suspend our rights to Healthius Corpus altogether.
Re:pros and cons (Score:5, Insightful)
1) Potentially die due to running out of blood (although many blood recipients aren't at death's door when they receive transfusions)
2) Potentially die post-transfusion from a heart attack or stroke
3) Potentially receive added nitric oxide, once study of this matter has moved forwards.
Shouldn't the goal of medical research be that we don't have medical beggars, but instead that anyone can have the best possible options?
Parent
Re: (Score:2)
Re:pros and cons (Score:4, Interesting)
If the results of this study bear out, then it may just mean that hospitals are even more likely to try to get a fresh donation prior to any surgery that may require a transfusion. E.R. is still going to have to deal with whatever supply they have on hand when someone comes through the doors, though maybe there are procedural changes they can make to help ensure that they use newer blood by preference?
Parent
no huhu (Score:4, Funny)
WARNING - May be Dug Company Propaganda! (Score:5, Informative)
Re: (Score:2)
An organization is often representative of its members. See RIAA, MPAA
Not that this study shouldn't bear some thought, but it perhaps take it with a grain of salt.
Blood doping? (Score:3, Insightful)
Perhaps the blood is not as efficient as it could be in transferring oxygen, but I would think that it is still pretty damn useful.
NO, pills and even some blood doping info (Score:3, Informative)
http://en.wikipedia.org/wiki/Endothelium-derived_relaxing_factor [wikipedia.org]
There are ways of going around this, like taking nitroglycerin pills
http://en.wikipedia.org/wiki/Glyceryl_tr [wikipedia.org]
I don't want to be a naysayer, but... (Score:2)
Donated blood works, just not as well (Score:2)
Re: (Score:2)
http://en.wikipedia.org/wiki/Blood_transfusion [wikipedia.org]
Early attempts
The first historical attempt at blood transfusion was described by the 15th-century chronicler Stefano Infessura. Infessura relates that, in 1492, as Pope Innocent VIII sank into a coma, the blood of three boys was infused into the dying pontiff (through the mouth, as the concept of circulation and methods for intravenous access did not exist at that time) at the suggestion of a physici
Wrong Chemical in summary (Score:5, Informative)
Re: (Score:2)
I hope they got it right the second time around- let me check. Nitrogen Dioxide? That doesn't sound right... nurse! Nurse! Nu
NO CARRIER
Re: (Score:2)
Quite right. The difference is pretty important.
Nitric Oxide is used to improve perfusion in people on respirators. It is particularly useful in premature babies in the NICU [google.com], whose lungs are not as well developed and have difficulty absorbing enough oxygen and can suffer from pulmonary hypertension. In general, NO relaxes the smooth muscle in arteries, making it a vasodilator. It is rapidly absorbed and deactivated by hemoglo
Re: (Score:2)
Possible implications on blood storage (Score:5, Insightful)
2. As with any study, an independent study should be done to see if this is verifiable and repeatable. This should be done by a lab that is not financially or otherwise linked to the NO additive firm aforementioned.
3. The other thing to look at is method of storage, temperature, and other conditions - did they conform to current standards, did they vary these elements, and was this independently audited?
more than just bias that I would be concerned abou (Score:3, Informative)
Well, not having read the study I can not comment on its significance; however, there is far more to blood transfusion dangers than NO depletion.
Lets get to some significant points: NO is produced locally at the tissues that need it.
RBC fragility is likely more significant than the effects of one vasodilator
Multiple unnecessary (or necessary) transfusions may lead to iron overload similar to that found in people with hemachromatosis
TRALI
I am not attacking their work, but t
Re: (Score:2)
Or they found the lack of NO in stored blood and made the product to solve the problem. It's fine to look for corroborating evidence, but scientists at drug companies are just like scientists everywhere else and they really don't just make shit up for money. Kneejerk doubt isn't any more rational or wise than kneejer
This is not a new concept (Score:4, Informative)
It's well known that packed red blood cells or whole blood is not as effective as fresh blood at transporting hemoglobin. This is because of several factors, notably shifts in 2,3-BPG, ATP, ADP during storage as well as partially due to the calcium citrate used to prevent clotting of the stored blood.
While it isn't ideal, our current method is by far the safest way to give blood, simply because you cannot screen blood for deadly pathogens in the time it takes for blood to start to degrade. While many people have researched ways to shift the binding characteristics of stored blood back to fresh blood, and with some success on manipulation of hemoglobin's oxygen binding curves, overall the clinical effect for patients has been minimal.
The nitrous-oxide pathway, to my knowledge, has not been tried yet, but I'd hate to have my blood pre-mixed with a drug that would kill a percentage of the patients who are candidates for blood transfusion. When someone is exsanguinating, you want to INCREASE their blood pressure, not decrease it.
On the other hand, in ischemic disease you do want to give nitro, in certain situations, but preferably not pre-mixed with the blood, and we already do this, just not in strokes, yet.
artificial blood has the same problem (Score:2)
Also.... (Score:2)
Yeah, it's definitely not very effective. (Score:2)
This is exactly why we need a place (Score:2)
I work for the American Red Cross (Score:5, Informative)
I work in I.T. for ARC, but previous to that, I worked on the front lines, collecting the blood.
Allow me to give you a mini-tour.
First, the donor is required to read and acknowledge that they've read the health history guidelines.
Then the donor is required to get their vitals checked, answer several health related questions.
At that point the donor is placed on the donor bed. Their information is rechecked for accuracy.
Their arm is scrubbed using a two-step method.
The venipuncture is performed.
Now here's the important part. The blood comes into the bad which is filled with an anti-coagulant solution, and for it to be a "good unit"...we can only collect so much blood/per anti-coag...the entire unit is measured by weight @ 610g +/- 5% (for a proper whole blood to anti-coag solution). I may be slightly off on the ratio, it's been a while.
Then the unit is packed on ice, and maintained at a constant temperature.
Then the blood goes to the production lab, where the platelets and plasma are expressed and harvested for other uses.
The red blood cells are then introduced to a red cell preservative, (this is the part that makes the blood viable for 42 days)
The units are then either flash frozen, or they're placed in quarantine until the test results are back from the NTL (national testing lab).
but here's the chink in the armor of the original poster's argument. Our blood supply is so low right now in the US, that his argument is a moot point. 99% of the time, the blood isn't even on the shelf that long. Every 2 seconds, someone in the U.S. needs a transfusion of packed red cells....someone like me, who is 0-, CMV-.....I'm pretty much fucked....there won't be any blood available for me. (so all you O-'s...please go donate...lol)...
Anyway....yes, units do lose their potency over time...but part of the process is to ensure that the donor is healthy, and this helps ensure that when the blood is needed it will be as potent as possible.
At the American Red Cross, we make every effort to make sure that there's blood available when it's needed, where it's needed, and provide the best quality units, at the cheapest price, and make every effort to ensure that it's potent, and safe....that's from the very top of the food chain all the way down the janitors...we all love what we do, and we save lives.
That's not to say that occasionally there might be a 1/1,000,000 unit that didn't do the job, but I like those odds
Donating to Yourself (Score:4, Interesting)
But if you donated blood in advance of surgery, and it were used within a few hours, you could get a credit for blood later on when you need it urgently. If everyone scheduled for surgery were required to donate blood in advance (if they were healthy enough to do so), there would be so much blood available all the time that the fresh stuff would never be in short supply.
The infrastructure is in place right now. The techniques are nearly the same, just a tiny little DB and fridge shuffling to keep the fresh stuff flowing, and discard the extra as it ages.
All that's required to permanently end the incessant "blood shortages" and blood drives that could work on something else instead, would be making these donations a requirement.
Re: (Score:3, Funny)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re:Got a lot to learn (Score:5, Informative)
Even now, blood transfusions are only used by doctors in the most critical situation and yes, storage and transfer of blood as well as the necessary screenings make it very difficult to get a 1) cheap and 2) reliable source of blood.
Some doctors even don't use blood transfusions at all (there are even some hospitals that don't give any blood for any reason) and use substitutes like volume expanders or oxygen carriers to get what the body needs (either a larger volume of blood or more carriers so a subject doesn't asphyxiate) or they use only parts of the blood that are deemed necessary (for example to clot your blood faster) and that are more safe than blood.
Blood is considered an organ, with transfusions you get issues like rejection just like you get (often) with liver transplants and giving somebody a large amount of foreign blood could also result in shock or death.
Parent
Re: (Score:2)
Taking this article to mean that all science is bullshit is a pretty fucking big leap. I guess what I'm saying is, you're an idiot.
Re: (Score:3, Insightful)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
it's called being responsible and taking the right precautions.
confidence has nothing to do with it.
Re: (Score:2)